1. Field of the Invention.
The present invention relates generally to endotracheal tubes, and artificial voicing systems.
2. Background of the invention.
Since the advent of ventilatory assistance with an endotracheal tube, patients have had to accept the sacrifice of speech that results from the tube being placed in the patient's trachea through the vocal cords. This loss of speech may result in great fear, frustration and withdrawal of the intubated patient. Also, as a result of this inability to speak, the patient is unable to communicate fully with the health care professional concerning his or her medical history or current symptoms. To compound this problem further, this inability to speak comes at a time when such medical information is often of vital importance.
Many techniques of communication have been substituted for speech in an effort to alleviate the anxiety of the patient and to facilitate health care delivery. These substitutes include lip reading, writing, and the use of hand signals. Unfortunately, few hospital staff people are able to lip read, and many times the ventilated patient lacks the strength or ability to write or use hand signals.
Communication can also be achieved through the use of artificial voicing systems. These systems typically include a sound generating device which produces a tone that is transmitted through a tube to the user's mouth and therein articulated into speech. This tone, therefore, takes the functional place of the user's vocal cords. Since speech is achieved with the patient articulating the tone into words in a normal manner, such speech systems have the advantage of being easily learned. However, since the tube must be positioned and held in the mouth, generally either by the patient or the health care professional, a problem is presented if the intubated patient lacks the physical ability to hold the tube in place. Furthermore, the health care professional may not have a free hand to devote to that job during all medical procedures.
A system for hands free operation is provided for by the Cooper-Rand intra oral speech device wherein the sound transmission tube is secured in place through attachment to either a headband or glasses worn by the patient. However, this additional mechanical support equipment requires time to be properly fitted to the patient and can be cumbersome for the patient to wear.
The Venti-Voice.TM. speech system also permits hands free operation through the use of a tone delivery tube that is inserted transnasally, allowing the tone to travel into the patient's oral cavity. This nasally held tube also prevents the inconvenience to the patient associated with the presence of a tube in their mouth while speaking and permits more accurate articulation of word sounds. However, the Venti-Voice.TM. system is primarily contemplated for use with tracheostomized patients. The separate nasally held tube can be awkward to use with an intubated patient wherein the endotracheal tube is also nasally inserted.
Certain artificial speech devices do not require a sound transmission tube. These hand held devices are placed against the patient's neck allowing the sound they produce to be projected through the neck tissue into the larynx and up towards the mouth. In addition to the problem of requiring a free hand for their operation, these devices are generally less effective than the tube systems in their ability to deliver a tone to the patient's mouth sufficient to produce audible speech. Various neck conditions, such as the presence of scar tissues or fat, can block the efficient transfer of sound through the neck. Furhermore, it takes more time for a patient to learn to use a neck held device to communicate effectively that it does for the patient to learn to use a tube speech system, and physically debilitated patients can find the use of neck held devices to be difficult or impossible.